The present disclosure relates to a simulation method and a simulation program for predicting the amount of damage due to ultraviolet rays in manufacturing a semiconductor device. In addition, the present disclosure relates to a semiconductor manufacturing apparatus which predicts the amount of damage due to ultraviolet rays and controls process conditions.
In manufacturing a semiconductor device, a process using plasma generated by high-frequency bias application has been widely performed.
In the plasma, collision of particles and interactive reactions with a chamber wall occur, and ions, radicals, and light are generated, in accordance with a structure of a process chamber and process conditions.
In relation to technical development for predicting and controlling damage to a film (crystal defects) caused when film is irradiated with ions, various techniques such as simulation methods, process methods, and apparatus configurations have been proposed.
In addition to the damage caused by the ions, there has been a concern regarding damage to the film due to light emitted from the plasma, particularly ultraviolet rays, namely ultraviolet (UV) and vacuum-ultraviolet (VUV) in recent years. Basic studies and monitoring techniques relating to the damage to the film due to the ultraviolet rays emitted from plasma have been domestically and internationally intensified.
Since semiconductor devices have decreased in thickness, and organic semiconductor devices and compound semiconductor devices have been widely developed recently, it has become desirable to develop techniques for predicting emission intensity in the ultraviolet wavelength region and quantitatively predict and control damage caused by ultraviolet rays.
For this reason, some methods for monitoring the ultraviolet rays and methods for predicting the amount of damage due to the ultraviolet rays in manufacturing a semiconductor device have been proposed in the related art.
For example, a method in which a sensor configured by layers of a silicon film and an oxide film is installed in a wafer or on a top panel of a plasma chamber to detect a hole generated by the ultraviolet rays incident on the sensor as induced current under application of negative bias has been proposed (see Japanese Unexamined Patent Application Publication Nos. 2009-283838 and 2009-59879).
By measuring variations in the induced current during a plasma process, it is possible to monitor the total ultraviolet (not dispersed) intensity in real time. In addition, the amount of damage is predicted while the ultraviolet intensity is used as an index.
In addition, a method for monitoring the ultraviolet rays emitted from an ultraviolet light in an ultraviolet cleaning apparatus for removing organic substances has been proposed (see Japanese Unexamined Patent Application Publication No. 62-122130).
Although ultraviolet rays with a wavelength of 254 nm are used for cleaning, there is a problem in that a sensor immediately deteriorates due to high emission intensity if monitoring is performed directly.
For this reason, in the proposed method, variations in the intensity at a wavelength of 254 nm, which is originally desired to be detected, are predicted without directly monitoring the wavelength of 254 nm, by monitoring as a reference an ultraviolet intensity at 313 nm, which is correlated with the wavelength of 254 nm and is of a lower intensity.